Damp in your home or building can only be caused by 3 ways: Penetrative Damp, Rising Damp or Condensation Damp. In the most simple terms they are as explained as follows: 1. Penetrative Damp: Water is entering your property through a hole/cavity. 2. Rising Damp: Coming up from the ground and breaking through your damp course (if you have one). 3. Condensation Damp: The House/Room is sweating and unable to breath and causing a build up moisture, thus causing walls/windows/ceilings to get damp.